High power telecommunication devices typically include a transmitter line-up including leaded high power electronic components. For example, multi-stage amplifier circuits are used to meet high level power requirements utilizing one or more high power amplifier transistors. The impedance, current drain and hence the efficiency of these components vary with frequency and transmit power level.
High power electronic components soldered to circuit boards, particularly circuit boards of portable devices, face issues with thermal dissipation and efficiency. Heat sinks are used in conjunction with these components to facilitate thermal dissipation, but depending on the load presented to the component, a parameter known as voltage standing wave ratio (VSWR) is created in the transmit path which introduces local heating of other devices on the circuit board. Depending on the magnitude and phase of the load, at certain frequencies, a significant amount of heating can occurs on the leads of the component. The heating, along with repeated cycles of transmit and receive, cause solder joints between the leads of the component and the circuit board to fail. This failure is characterized by a formation of cracks that propagate throughout the solder joint until the joint is completely cracked. The result is an open impedance at the component lead resulting in arcing and failure of the device and circuit board.
Accordingly, there is a need to reduce the propensity of the solder joints to crack and fail during cyclic loading of a leaded high power component.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.